Methods and systems for fitting an electro-acoustic stimulation system to a patient

ABSTRACT

An exemplary system includes 1) a stimulation management facility configured to direct an electro-acoustic stimulation (“EAS”) system to concurrently apply acoustic stimulation to a patient by way of a loudspeaker and electrical stimulation to the patient by way of an electrode, and 2) a fitting facility communicatively coupled to the stimulation management facility and configured to detect an interaction between the acoustic stimulation and the electrical stimulation, and set one or more control parameters governing an operation of the EAS system based on the detected interaction. Corresponding systems and methods are also disclosed.

RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 14/386,330, filed Sep. 18, 2014, which applicationis a U.S. National Stage Entry of PCT Application No. PCT/US2013/033604,filed Mar. 22, 2013, which application claims the benefit of U.S.Provisional Patent Application No. 61/614,129, filed on Mar. 22, 2012,and entitled “Methods and Systems for Fitting an Electro-acousticStimulation System to a Patient,” the contents of which are herebyincorporated by reference in their entirety.

BACKGROUND INFORMATION

Many hearing loss patients have some degree of residual hearing in thelow frequencies (e.g., below 1 kHz) and a severe hearing loss in thehigh frequencies (e.g., above 1 kHz). These people cannot benefit fromtraditional hearing aid amplification because of the severity of thehearing loss in the high frequencies. Nor are they classic cochlearimplant candidates, because of their mostly intact low frequencyresidual hearing.

For this group of people, electro-acoustic stimulation (“EAS”) systemshave been developed that provide such patients with the ability toperceive both low and high frequencies. Electro-acoustic stimulationcombines the functionality of a hearing aid and a cochlear implanttogether in the same ear by providing acoustic stimulationrepresentative of low frequency audio content and electrical stimulationrepresentative of high frequency content. The auditory nerve combinesthe acoustic and electric stimuli into one auditory signal. Results ofvarious studies have shown that electro-acoustic stimulation may enhancespeech understanding, pitch discrimination, and music appreciation.

Unfortunately, the acoustic and electrical stimulation provided by anEAS system may sometimes negatively interact with each other, therebydegrading the listening experience of an EAS patient. For example, theelectrical stimulation provided by an EAS system may have a suppressiveeffect on the acoustic stimulation provided by the EAS system (e.g., bypreventing the neurons in the apical region of the cochlea fromresponding to the acoustic stimulation). Likewise, the acousticstimulation provided by an EAS system may have a suppressive interactiveeffect on the electrical stimulation provided by the EAS system.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various embodiments and are a partof the specification. The illustrated embodiments are merely examplesand do not limit the scope of the disclosure. Throughout the drawings,identical or similar reference numbers designate identical or similarelements.

FIG. 1 illustrates an exemplary electro-acoustic stimulation (“EAS”)system according to principles described herein.

FIG. 2 illustrates a schematic structure of the human cochlea.

FIG. 3 illustrates an exemplary fitting system according to principlesdescribed herein.

FIG. 4 shows an exemplary baseline response that may occur in responseto application of acoustic stimulation by itself and two possible evokedresponses that may occur in response to concurrent application of thesame acoustic stimulation together with electrical stimulation accordingto principles described herein.

FIG. 5 is a flowchart illustrating an exemplary method of evaluating andaccounting for an interactive effect that electrical stimulation mayhave on acoustic stimulation in an EAS system according to principlesdescribed herein.

FIG. 6 shows an exemplary configuration in which the fitting system ofFIG. 3 is at least partially implemented by a fitting devicecommunicatively coupled to an EAS device according to principlesdescribed herein.

FIG. 7 illustrates an exemplary bimodal cochlear implant systemaccording to principles described herein.

FIG. 8 illustrates an exemplary method of fitting an EAS system to apatient according to principles described herein.

FIG. 9 illustrates another exemplary method of fitting an EAS system toa patient according to principles described herein.

FIG. 10 illustrates another exemplary method of fitting an EAS system toa patient according to principles described herein.

FIG. 11 illustrates an exemplary computing device according toprinciples described herein.

DETAILED DESCRIPTION

Methods and systems for fitting an electro-acoustic stimulation (“EAS”)system to a patient are described herein. As will be described below, afitting system may 1) direct the EAS system to concurrently applyacoustic stimulation to a patient by way of a loudspeaker and electricalstimulation to the patient by way of an electrode located within acochlea of the patient during a fitting session, 2) detect aninteraction between the acoustic stimulation and the electricalstimulation during the fitting session, and 3) set, during the fittingsession, one or more control parameters governing an operation of theEAS system based on the detected interaction.

For example, the fitting system may determine that the electricalstimulation has a suppressive interactive effect on the acousticstimulation. Based on this determination, the fitting system may adjustone or more properties of the electrical stimulation in a manner thatreduces the suppressive interactive effect of the electrical stimulationon the acoustic stimulation or disable the electrode for standardelectrical stimulation subsequent to the fitting session (e.g., duringone or more subsequent electro-acoustic stimulation sessions).Alternatively, the fitting system may determine that the acousticstimulation has a suppressive interactive effect on the electricalstimulation. Based on this determination, the fitting system may adjustone or more properties of the acoustic stimulation in a manner thatreduces the suppressive interactive effect of the acoustic stimulationon the electrical stimulation.

In some examples, the fitting system may determine that the electricalstimulation delivered by way of the electrode actually enhances theacoustic stimulation. In this case, as described in more detail below,the fitting system may designate the electrode as an enhancing electrodethrough which enhancing electrical stimulation is to be appliedsubsequent to the fitting session. Likewise, the fitting system maydetermine that the acoustic stimulation enhances the electricalstimulation delivered by way of the electrode. In this case, the fittingsystem may direct the EAS system to apply the acoustic stimulation everytime electrical stimulation is applied by way of the electrodesubsequent to the fitting session.

In some examples, the fitting system may determine that the electricalstimulation delivered by way of the electrode does not have anyinteractive effect on the acoustic stimulation. In this case, thefitting system may designate the electrode as an electrode through whichstandard electrical stimulation is to be applied subsequent to thefitting session.

As will be described below, the methods and systems described herein mayfacilitate an objective determination of an interactive effect thatelectrical stimulation has on acoustic stimulation and vice versa. Assuch, the methods and systems may be used to fit EAS systems to adultsas well as to children and other types of patients who have difficultyproviding subjective feedback during a fitting session. The methods andsystems described herein may also determine (and/or aid a clinician indetermining) various EAS parameters such as, but not limited to,crossover frequencies, intensity levels at the crossover frequencies,slopes of filters at the crossover frequencies, and/or other EASparameters used to fit an EAS system to a patient.

FIG. 1 illustrates an exemplary EAS system 100. As shown, EAS system 100may include an EAS device 102, a cochlear implant 104, an electrode lead106 having a plurality of electrodes 108 disposed thereon, and aloudspeaker 110 (also referred to as a receiver).

EAS device 102 may include any suitable device configured to processaudio content (e.g., one or more audio signals) presented to a patientand provide electrical and/or acoustic stimulation representative of theaudio signals to the patient. In some examples, EAS device 102 may beimplemented by an externally worn unit (e.g., a behind-the-ear device, abody worn device, etc.).

As mentioned, EAS device 102 may be used when the patient has someresidual some hearing in the low frequencies (e.g., below 1000 Hz) andsevere hearing loss in the high frequencies (e.g., above 1000 Hz). Tothis end, EAS device 102 may direct cochlear implant 104 to applyelectrical stimulation representative of audio content included in arelatively high frequency band (e.g., above 1000 Hz) to one or morestimulation sites within the patient by way of one or more of electrodes108 and loudspeaker 110 to apply acoustic stimulation representative ofaudio content included in a relatively low frequency band (e.g., below1000 Hz) to the patient.

Cochlear implant 104 may include any suitable auditory prosthesisconfigured to be at least partially implanted within a patient as mayserve a particular implementation. For example, cochlear implant 104 mayinclude an implantable cochlear stimulator, a brainstem implant and/orany other type of auditory prosthesis. EAS device 102 and cochlearimplant 104 may communicate by way of any suitable wired or wirelesscommunication channel.

Electrode lead 106 may be implanted within the patient such thatelectrodes 108 are in communication with stimulation sites within thecochlea. In this configuration, EAS device 102 may direct cochlearimplant 104 to apply electrical stimulation representative of an audiosignal to one or more stimulation sites within the patient by way of oneor more of electrodes 108. As used herein, the term “in communicationwith” refers to electrodes 108 being adjacent to, in the generalvicinity of, in close proximity to, directly next to, or directly on theone or more stimulation sites. Any number of electrodes 108 (e.g.,sixteen) may be disposed on lead 106 as may serve a particularimplementation.

FIG. 2 illustrates a schematic structure of the human cochlea 200 intowhich lead 106 may be inserted. As shown in FIG. 2, the cochlea 200 isin the shape of a spiral beginning at a base 202 and ending at an apex204. Within the cochlea 200 resides auditory nerve tissue 206, which isdenoted by Xs in FIG. 2. The auditory nerve tissue 206 is organizedwithin the cochlea 200 in a tonotopic manner. Relatively low frequenciesare encoded at or near the apex 204 of the cochlea 200 (referred to asan “apical region”) while relatively high frequencies are encoded at ornear the base 202 (referred to as a “basal region”). Hence, electricalstimulation applied by way of electrodes disposed within the apicalregion (i.e., “apical electrodes”) may result in the patient perceivingrelatively low frequencies and electrical stimulation applied by way ofelectrodes disposed within the basal region (i.e., “basal electrodes”)may result in the patient perceiving relatively high frequencies. Thedelineation between the apical and basal electrodes on a particularelectrode lead may vary depending on the insertion depth of the lead,the anatomy of the patient's cochlea, and/or any other factor as mayserve a particular implementation.

Once a patient has been with EAS system 100, and during follow-up testand checkups thereafter, it may be necessary to fit EAS system 100 tothe patient. Such “fitting” may include setting and/or adjustment of oneor more control parameters governing an operation of EAS system 100. Tofacilitate fitting of EAS system 100 to a patient, a fitting system maybe selectively and communicatively coupled to EAS system 100. As will bedescribed below, the fitting system may additionally or alternatively beimplemented by EAS device 102.

FIG. 3 illustrates an exemplary fitting system 300. As shown in FIG. 3,fitting system 300 may include a stimulation management facility 302, afitting facility 304, and a storage facility 306, which may be incommunication with one another using any suitable communicationtechnologies. One or more of facilities 302-306 may include one or morecomputing devices and/or processors configured to perform one or more ofthe functions described herein. Facilities 302-306 will now be describedin more detail.

Stimulation management facility 302 may be configured to perform one ormore acoustic and/or electrical stimulation management operations. Forexample, stimulation management facility 302 may be configured todirect, during a fitting session, an EAS system (e.g., EAS system 100)to concurrently apply acoustic stimulation to a patient by way of aloudspeaker (e.g., loudspeaker 110 or any other suitable transducer,headphone, earphone, and/or specialized hearing aid) and electricalstimulation to the patient by way of an electrode (e.g., one ofelectrodes 108) located within a cochlea of the patient. As used herein,a “fitting session” refers to a period of time during which one or morefitting operations are performed. The acoustic and electricalstimulation may have any suitable characteristic as may serve aparticular implementation. For example, the acoustic stimulation mayinclude a relatively low frequency tone burst (e.g., a 125 Hz toneburst) and the electrical stimulation may include monopolar stimulation.The electrode to which the electrical stimulation is applied may be anyelectrode located within the cochlea of the patient (e.g., the mostapical electrode).

Fitting facility 304 may be configured to perform one or more fittingoperations associated with an EAS system (e.g., EAS system 100). Forexample, fitting facility 304 may detect an interaction between theacoustic stimulation and the electrical stimulation applied by an EASsystem at the direction of stimulation management facility 302. Fittingfacility 304 may then set one or more control parameters governing anoperation of the EAS system based on the detected interaction.

Storage facility 306 may be configured to maintain fitting data 308generated and/or utilized by stimulation management facility 302 and/orfitting facility 304. Storage facility 306 may be configured to maintainadditional or alternative data as may serve a particular implementation.

Various examples of detecting an interaction between acoustic andelectrical stimulation and then setting one or more control parametersgoverning an operation of an EAS system based on the detectedinteraction will now be described.

In some examples, fitting facility 304 may determine an interactiveeffect that the electrical stimulation has on the acoustic stimulationand set one or more electrical stimulation control parameters governingan operation of the EAS system based on the determined interactiveeffect. As used herein, “electrical stimulation control parameters”refer to control parameters that govern a manner in which an EAS systemapplies electrical stimulation by way of one or more electrodes disposedwithin a cochlea of a patient.

Fitting facility 304 may determine an interactive effect that theelectrical stimulation has on the acoustic stimulation in any suitablemanner. To illustrate, fitting facility 304 may determine an interactiveeffect that the electrical stimulation has on the acoustic stimulationby measuring an evoked response that occurs in response to theconcurrent application of the acoustic stimulation and the electricalstimulation and comparing the evoked response to a baseline responsethat occurs in response to an application of the acoustic stimulation byitself. As used herein, an “evoked response” refers to an intracochlearhair-cell response (i.e., cochlear microphonics), a neural response(e.g., an auditory nerve response, a brainstem response, a compoundaction potential), and/or any other type of neural or physiologicalresponse that may occur within a patient in response to application ofacoustic and/or electrical stimulation to the patient. A “baselineresponse” refers to an evoked response that occurs in response toapplication of a single type of stimulus (e.g., acoustic stimulationonly).

To illustrate, FIG. 4 shows an exemplary baseline response 402 that mayoccur in response to application of acoustic stimulation by itself andtwo possible evoked responses 404-1 and 404-2 that may occur in responseto concurrent application of the same acoustic stimulation together withelectrical stimulation. As shown, evoked response 404-1 is less thanbaseline response 402 (i.e., evoked response 404-1 has a steady stateamplitude that is less than a steady state amplitude of baselineresponse 402). Hence, if concurrent application of the acoustic andelectrical stimulation results in an evoked response similar to evokedresponse 404-1 (i.e., if the evoked response is less than baselineresponse 402), fitting facility 304 may determine that the electricalstimulation has a suppressive interactive effect on the acousticstimulation. Conversely, evoked response 404-2 is greater than baselineresponse 402 (i.e., evoked response 404-2 has a steady state amplitudethat is greater than a steady state amplitude of baseline response 402).Hence, if concurrent application of the acoustic and electricalstimulation results in an evoked response similar to evoked response404-2 (i.e., if the evoked response is greater than baseline response402), fitting facility 304 may determine that the electrical stimulationhas an enhancing interactive effect on the acoustic stimulation.

A baseline response (e.g., baseline response 402) may be measured ordetermined by fitting facility 304 in any suitable manner. For example,fitting facility 304 may measure a baseline response that occurs inresponse to application of acoustic stimulation by directing an EASsystem to apply the acoustic stimulation, recording an evoked responsethat occurs in response to the application of the acoustic stimulation,designating the evoked response that occurs in response to theapplication of the acoustic stimulation as the baseline response, andstoring data representative of the baseline response. The acousticstimulation used to elicit the baseline response may include anysuitable type of acoustic stimulation as may serve a particularimplementation. For example, the acoustic stimulation used to elicit thebaseline response may include a relatively low frequency tone burst(e.g., a 125 Hz tone burst).

An evoked response may be recorded in any suitable manner using anysuitable combination of recording electrodes. For example, anintracochlear hair-cell response (cochlear microphonics) may be recordedusing one or more electrodes positioned within the cochlea (e.g., one ormore of electrodes 108), one or more electrodes positioned within theround window, and/or one or more electrodes positioned at any othersuitable location relatively near the cochlea. Likewise, an auditorynerve response and/or a compound action potential may be recorded usingone or more electrodes positioned within or near the cochlea. It will berecognized that the electrodes used to record the evoked response may bedisposed on a lead that has been inserted into the cochlea (e.g., lead106) and/or on a fly lead that has been positioned at any other suitablelocation within the patient.

An evoked response may be recorded in any suitable manner using anysuitable combination of recording electrodes. For example, anintracochlear hair-cell response may be recorded in accordance with oneor more cochlear microphonics techniques using one or more electrodespositioned within the cochlea (e.g., one or more of electrodes 108), oneor more electrodes positioned within the round window, and/or one ormore electrodes positioned at any other suitable location relativelynear the cochlea. Likewise, an auditory nerve response and/or a compoundaction potential may be recorded using one or more electrodes positionedwithin or near the cochlea. It will be recognized that the electrodesused to record the evoked response may be disposed on a lead that hasbeen inserted into the cochlea (e.g., lead 106) and/or on a fly leadthat has been positioned at any other suitable location within thepatient.

In some examples, one or more electrodes located external to the patientmay be used to record an evoked response. For example, a brainstemresponse may be recorded using one or more non-invasive electrodes thathave been affixed externally to the head of the patient.

Additionally or alternatively, fitting facility 304 may determine aninteractive effect that the electrical stimulation has on the acousticstimulation based on subjective feedback provided by the patient. Forexample, fitting facility 304 may direct the EAS system to first presentonly the acoustic stimulation to the patient. Immediately thereafter,fitting facility 304 may direct the EAS system to concurrently presentthe same acoustic stimulation together with electrical stimulation tothe patient. A clinician may ask the patient to compare the two types ofstimulation (i.e., the acoustic stimulation by itself versus acousticstimulation together with electrical stimulation). In response, thepatient may indicate that one type of stimulation was louder, clearer,or otherwise different than the other type of stimulation. In responseto this subjective feedback, the clinician may provide datarepresentative of the interactive effect that the electrical stimulationhas on the acoustic stimulation to fitting facility 304 (e.g., by way ofone or more graphical user interfaces provided by fitting facility 304).

As another example, fitting facility 304 may determine an interactiveeffect that the electrical stimulation has on the acoustic stimulationby performing a spectral ripple test with respect to the ear associatedwith the EAS system. During an exemplary spectral ripple test, aspectral ripple test score is generated for the ear that indicates thesmallest spectral contrast of a spectrally modulated stimulus that theear is capable of detecting. Exemplary spectral ripple tests that may beused in accordance with the methods and systems described herein aredescribed more fully in U.S. Pat. No. 8,027,734, which patent isincorporated herein by reference in its entirety.

To illustrate, a spectral ripple test may be performed by determiningthe smallest spectral contrast of a spectrally modulated acousticstimulus that the ear is capable of detecting with and without theconcurrent application of an electrical stimulus. If the spectral rippletest score improves in the presence of the electrical stimulus, fittingfacility 304 may determine that the electrical stimulation has anenhancing interactive effect on the acoustic stimulation. Conversely, ifthe spectral ripple test score decreases in the presence of theelectrical stimulus, fitting facility 304 may determine that theelectrical stimulation has a suppressive interactive effect on theacoustic stimulation. If the spectral ripple test score does not changein the presence of the electrical stimulus, fitting facility 304 maydetermine that the electrical stimulation does not have either asuppressive or an enhancing interactive effect on the acousticstimulation.

Once fitting facility 304 has determined the type of interactive effectthat the electrical stimulation has on the acoustic stimulation (i.e.,whether the electrical stimulation has a suppressive interactive effect,an enhancing interactive effect, or no interactive effect on theacoustic stimulation), fitting facility 304 may set one or moreelectrical stimulation control parameters governing an operation of theEAS system based on the determined interactive effect.

To illustrate, fitting facility 304 may determine that the electricalstimulation has a suppressive interactive effect on the acousticstimulation. In response, fitting facility 304 may adjust one or moreproperties of the electrical stimulation in a manner that reduces thesuppressive interactive effect of the electrical stimulation on theacoustic stimulation. For example, the intensity level, pulse width,and/or rate of the electrical stimulation may be adjusted until thesuppressive interactive effect is minimized. It will be recognized thatany other characteristic of the electrical stimulation may be adjustedin order to minimize the suppressive interactive effect of theelectrical stimulation on the acoustic stimulation as may serve aparticular implementation. Fitting facility 304 may then direct the EASsystem to limit the type of electrical stimulation provided by way ofthe electrode subsequent to the fitting session to that defined by theadjusted one or more parameters.

In some alternative examples, fitting facility 304 may designate theelectrode through which the suppressive electrical stimulation isapplied as being disabled subsequent to the fitting session. In thismanner, electrical stimulation will not be applied by way of thedesignated electrode during normal operation of the EAS system (i.e.,while the EAS system is operating in a non-fitting mode). Rather,acoustic stimulation will be used to represent sound within thefrequency range associated with the electrode.

In some examples, fitting facility 304 may first adjust one or moreproperties of the electrical stimulation provided by way of a particularelectrode in an attempt to reduce (e.g., minimize or eliminate) thesuppressive interactive effect that the electrical stimulation has onthe acoustic stimulation. If fitting facility 304 determines thatadjustment of the one or more properties of the electrical stimulationdoes not satisfactorily reduce the suppressive interactive effect of theelectrical stimulation on the acoustic stimulation, fitting facility 304may then designate the electrode as being disabled subsequent to thefitting session.

To illustrate, fitting facility 304 may determine that electricalstimulation provided by way of the most apical electrode has asuppressive interactive effect on the acoustic stimulation. In response,fitting facility 304 may adjust one or more properties of the electricalstimulation provided by way of the most apical electrode. If thisadjustment does not reduce the suppressive interactive effect of theelectrical stimulation on the acoustic stimulation (which may bedetermined by recording one or more additional evoked responses afterthe one or more properties have been adjusted), fitting facility 304 maydesignate the most apical electrode as being disabled subsequent to thefitting session.

In some examples, fitting facility 304 may determine that the electricalstimulation delivered by way of a particular electrode has an enhancinginteractive effect on the acoustic stimulation. In response, fittingfacility 304 may designate the electrode as an enhancing electrodethrough which enhancing electrical stimulation is to be appliedsubsequent to the fitting session.

As used herein, “enhancing stimulation” refers to any type of electricalstimulation configured to enhance acoustic stimulation. For example,enhancing stimulation may include sub-threshold electrical stimulation(i.e., electrical stimulation that has a stimulation level that is lessthan a threshold level required for the patient to perceive theelectrical stimulation). Concurrent application of sub-thresholdelectrical stimulation by way of an electrode together with acousticstimulation may enhance the acoustic stimulation in a variety of ways.For example, the sub-threshold electrical stimulation may lower anacoustic detection threshold of the patient. As used herein, an“acoustic detection threshold” of a patient refers to a sound level ofacoustic stimulation that is required for the patient to detect theacoustic stimulation. Hence, the sub-threshold electrical stimulationmay make it easier for the patient to detect the acoustic stimulation.Sub-threshold electrical stimulation may additionally or alternativelyserve to maintain patency (i.e., inhibit neuropathy) of hearing nervecells located in the region of the cochlea that is associated with theelectrode.

The EAS system may apply enhancing stimulation by way of the designatedenhancing electrode in any suitable way. For example, EAS device 102 maydirect cochlear implant 104 to apply steady-state electrical stimulationby way of the designated electrode during the application of theacoustic stimulation. As another example, EAS device 102 may directcochlear implant 104 to apply sporadic electrical stimulation by way ofthe designated electrode during the application of the acousticstimulation. As another example, EAS device 102 may direct cochlearimplant 104 to apply periodic electrical stimulation by way of thedesignated electrode during the application of the acoustic stimulation.Each type of enhancing stimulation may include monopolar, bipolar,multipolar, and/or any other type of electrical stimulation as may servea particular implementation.

In some examples, fitting facility 304 may determine that the electricalstimulation delivered by way of a particular electrode does not haveeither a suppressive or enhancing interactive effect on the acousticstimulation. In this case, fitting facility 304 may designate theelectrode as an electrode through which standard electrical stimulationis to be applied subsequent to the fitting session. As used herein,“standard electrical stimulation” refers to electrical stimulation usedto represent audio content presented to the patient. Hence, electricalstimulation may be applied by way of the designated electrode torepresent audio content having a frequency included within a range offrequencies associated with that electrode.

FIG. 5 is a flowchart illustrating an exemplary method of evaluating andaccounting for an interactive effect that electrical stimulation mayhave on acoustic stimulation in an EAS system. While FIG. 5 illustratesexemplary steps according to one embodiment, other embodiments may omit,add to, reorder, and/or modify any of the steps shown in FIG. 5. One ormore of the steps shown in FIG. 5 may be performed by fitting system 300or any implementation thereof during a fitting session.

In step 502, a fitting system determines an interactive effect thatelectrical stimulation delivered by way of a particular electrode has onacoustic stimulation that is concurrently delivered to a patient. Step502 may be performed in any of the matters described herein. Forexample, step 502 may be performed objectively (e.g., by measuring oneor more evoked responses elicited by concurrent application of theacoustic and electrical stimulation) or subjectively (e.g., by applyinga spectral ripple test to the patient).

In step 504, the fitting system determines whether an interactionbetween the electrical stimulation and the acoustic stimulation exists.If there is no interaction (i.e., the electrical stimulation does nothave an interactive effect on the acoustic stimulation), the fittingsystem designates the electrode as an electrode through which standardelectrical stimulation is to be applied subsequent to the fittingsession in step 506.

If the fitting system determines that an interaction between theelectrical stimulation and the acoustic stimulation exists, the fittingsystem determines whether the interaction is enhancing or suppressive instep 508. If the interaction is enhancing (i.e., the electricalstimulation has an enhancing effect on the acoustic stimulation), thefitting system designates the electrode as an enhancing electrode instep 510. However, if the interaction is suppressive (i.e., theelectrical stimulation has a suppressive effect on the acousticstimulation), the fitting system may adjust one or more properties ofthe electrical stimulation in step 512. If a satisfactory reduction inthe suppressive interactive effect is realized by the adjustment of theone or more properties of the electrical stimulation (Yes; step 514),the fitting system designates the electrode as an electrode throughwhich standard electrical stimulation is to be applied subsequent to thefitting session (i.e., step 506). However, if a satisfactory reductionin a suppressive interactive effect is not realized by the adjustment ofthe one or more properties of the electrical stimulation (No; step 514),the fitting system disables the electrode in step 516.

Returning to FIG. 3, in some examples, fitting facility 304 maydetermine an interactive effect that the acoustic stimulation has on theelectrical stimulation and set one or more acoustic stimulation controlparameters governing an operation of the EAS system based on thedetermined interactive effect. As used herein, “acoustic stimulationcontrol parameters” refer to control parameters that govern a manner inwhich an EAS system applies acoustic stimulation to a patient.

Fitting facility 304 may determine an interactive effect that theacoustic stimulation has on the electrical stimulation in any suitablemanner. To illustrate, fitting facility 304 may determine an interactiveeffect that the acoustic stimulation has on the electrical stimulationby measuring an evoked response that occurs in response to theconcurrent application of the acoustic stimulation and the electricalstimulation and comparing the evoked response to a baseline responsethat occurs in response to an application of the electrical stimulationby itself.

For example, if the evoked response is greater than the baselineresponse, fitting facility 304 may determine that the acousticstimulation has an enhancing interactive effect on the electricalstimulation. Conversely, if the evoked response is less than thebaseline response, fitting facility 304 may determine that the acousticstimulation has a suppressive interactive effect on the electricalstimulation. If the evoked response is substantially equal to thebaseline response, fitting facility 304 may determine that the acousticstimulation has substantially no interactive effect on the electricalstimulation. It will be recognized that the evoked response and baselineresponse may be generated and measured in a manner that is similar tothat described above in connection with FIG. 4.

In some examples, fitting facility 304 may determine an interactiveeffect that the acoustic stimulation has on the electrical stimulationbased on subjective feedback provided by the patient. This may beperformed in a similar manner as that described above.

Once fitting facility 304 has determined the type of interactive effectthat the acoustic stimulation has on the electrical stimulation (i.e.,whether the acoustic stimulation has a suppressive interactive effect,an enhancing interactive effect, or no interactive effect on theelectrical stimulation), fitting facility 304 may set one or moreacoustic stimulation control parameters governing an operation of theEAS system based on the determined interactive effect.

To illustrate, fitting facility 304 may determine that the acousticstimulation has a suppressive interactive effect on the electricalstimulation. In response, fitting facility 304 may adjust one or moreproperties of the acoustic stimulation in a manner that reduces thesuppressive interactive effect of the acoustic stimulation on theelectrical stimulation. For example, the intensity level, duration,and/or frequency of the acoustic stimulation may be adjusted until thesuppressive interactive effect is minimized. It will be recognized thatany other characteristic of the acoustic stimulation may be adjusted inorder to minimize the suppressive interactive effect of the acousticstimulation on the electrical stimulation as may serve a particularimplementation.

In some examples, if the adjustment of the one or more properties of theacoustic stimulation does not result in a satisfactory reduction in thesuppressive interactive effect, fitting facility 304 may direct the EASsystem to not apply the acoustic stimulation while the electricalstimulation is delivered subsequent to the fitting session (i.e., duringa normal operation of the EAS system).

As another example, fitting facility 304 may determine that the acousticstimulation has an enhancing interactive effect on the electricalstimulation. In response, fitting facility 304 may direct the EAS systemto apply the acoustic stimulation while the electrical stimulation isdelivered subsequent to the fitting session (i.e., during a normaloperation of the EAS system).

In some examples, fitting facility 304 may determine that the acousticstimulation does not have either a suppressive or enhancing interactiveeffect on the electrical stimulation. In this case, fitting facility 304directs the EAS system to not apply the acoustic stimulation while theelectrical stimulation is delivered subsequent to the fitting session(i.e., during a normal operation of the EAS system). This may allow theEAS system to conserve power during normal operation.

While the functions of determining an interactive effect that theelectrical stimulation has on the acoustic stimulation and determiningan interactive effect that the acoustic stimulation has on theelectrical stimulation have been described separately, it will berecognized that fitting facility 304 may concurrently determine theinteractive effect that each type of stimulation has on the other.Fitting facility 304 may then set one or more electrical and/or acousticstimulation parameters based on the determined interactive effect.

In some examples, fitting facility 304 may determine an optimalcrossover frequency associated with the acoustic stimulation and theelectrical stimulation based on the detected interaction between theacoustic stimulation and the electrical stimulation. As used herein, a“crossover frequency” refers to a boundary frequency that separatesfrequencies represented to the patient by acoustic stimulation andfrequencies represented to the patient by electrical stimulation. Forexample, fitting facility 304 may determine that acoustic stimulationevokes a robust hair cell and neural responses until 450 Hz, the apicalmost electrode can start providing stimulation around that frequency,provided there is no suppression of the acoustic response. In casesuppression is observed, the fitting system may adjust one or moreproperties of the electrical stimulation as was the case in step 512. Ifa satisfactory reduction in the suppressive interactive effect isrealized by the adjustment of the one or more properties of theelectrical stimulation (Yes; step 514), the fitting system designatesthe electrode as an electrode through which standard electricalstimulation is to be applied subsequent to the fitting session. However,if a satisfactory reduction in a suppressive interactive effect is notrealized by the adjustment of the one or more properties of theelectrical stimulation (No; step 514), the fitting system disables theelectrode in step 516. The next electrode is then selected to providestimulation around 450 Hz provided there are no suppressive effectsobserved again. Various other properties (e.g., intensity levels at thecrossover frequency, a slope of one or more filters at the crossoverfrequency, and/or other EAS parameters used to fit an EAS system to apatient) associated with the crossover frequency may also be determinedbased on the detected interaction.

Fitting system 300 may be implemented by one or more components of EASsystem 100. For example, fitting system 300 may be implemented entirelyby EAS device 102. To illustrate, EAS device 102 may periodicallyanalyze an interaction that occurs between acoustic and electricalstimulation and adjust one or more control parameters accordingly. Inthis case, the term “fitting session” may refer to the period of timeduring which EAS device 102 performs the analysis.

Alternatively, fitting system 300 may be at least partially implementedby a fitting device selectively and communicatively coupled to EASdevice 102. To illustrate, FIG. 6 shows an exemplary configuration 600in which fitting system 300 is at least partially implemented by afitting device 602 communicatively coupled to EAS device 102. Fittingdevice 602 may implemented by any suitable combination of computing andcommunication devices including, but not limited to, a fitting station,a personal computer, a laptop computer, a handheld device, a mobiledevice (e.g., a mobile phone), and/or any other suitable component asmay serve a particular implementation. In some examples, fitting device602 may provide one or more graphical user interfaces (“GUIs”) withwhich a clinician or other user may interface in order to fit EAS system100 to the patient.

In some examples, fitting system 300 may be used to understand andevaluate interactions between acoustic and electrical stimulation in abimodal cochlear implant system. FIG. 7 illustrates an exemplary bimodalcochlear implant system 700 that may be used by a bimodal cochlearimplant patient (i.e., a patient fitted with a cochlear implant for oneear and an acoustic hearing instrument for the other ear). As shown,bimodal cochlear implant system 700 may include a sound processor 702, acochlear implant 704, and an electrode lead 706 having a plurality ofelectrodes 708 disposed thereon. Bimodal cochlear implant system 700 mayalso include a hearing instrument 710 communicatively coupled to soundprocessor 702. Hearing instrument 710 may include any type of acoustichearing aid as may serve a particular implementation.

Cochlear implant 704 may be used to apply electrical stimulation to oneof the ears of the patient and hearing instrument 710 may be used toapply acoustic stimulation to the other ear of the patient. Bothcochlear implant 704 and hearing instrument 710 may be controlled bysound processor 702, which may receive and process audio content.

In some examples, fitting system 300 may be used to detect and evaluateinteractions between the ipsilateral (same ear) or contralateral(opposite ear) acoustic stimulation provided by hearing instrument 710and the electrical stimulation provided by cochlear implant 704. To thisend, fitting system 300 may be at least partially implemented by soundprocessor 702 and/or a fitting device (which may be similar to fittingdevice 602) selectively and communicatively coupled to sound processor702.

FIG. 8 illustrates an exemplary method 800 of fitting an EAS system to apatient. While FIG. 8 illustrates exemplary steps according to oneembodiment, other embodiments may omit, add to, reorder, and/or modifyany of the steps shown in FIG. 8. One or more of the steps shown in FIG.8 may be performed by fitting system 300 and/or any implementationthereof.

In step 802, a fitting system directs, during a fitting session, an EASsystem to concurrently apply acoustic stimulation to a patient by way ofa loudspeaker and electrical stimulation to the patient by way of anelectrode located within a cochlea of the patient. Step 802 may beperformed in any of the ways described herein.

In step 804, the fitting system detects, during the fitting session, aninteraction between the acoustic stimulation and the electricalstimulation. Step 804 may be performed in any of the ways describedherein.

In step 806, the fitting system sets, during the fitting session, one ormore control parameters governing an operation of the EAS system basedon the detected interaction. Step 806 may be performed in any of theways described herein.

FIG. 9 illustrates another exemplary method 900 of fitting an EAS systemto a patient. While FIG. 9 illustrates exemplary steps according to oneembodiment, other embodiments may omit, add to, reorder, and/or modifyany of the steps shown in FIG. 9. One or more of the steps shown in FIG.9 may be performed by fitting system 300 and/or any implementationthereof.

In step 902, a fitting system directs, during a fitting session, an EASsystem to concurrently apply acoustic stimulation to a patient by way ofa loudspeaker and electrical stimulation to the patient by way of anelectrode located within a cochlea of the patient. Step 902 may beperformed in any of the ways described herein.

In step 904, the fitting system determines, during the fitting session,an interactive effect that the electrical stimulation has on theacoustic stimulation. Step 904 may be performed in any of the waysdescribed herein.

In step 906, the fitting system sets, during the fitting session, one ormore electrical stimulation control parameters governing an operation ofthe EAS system based on the determined interactive effect. Step 906 maybe performed in any of the ways described herein.

FIG. 10 illustrates another exemplary method 1000 of fitting an EASsystem to a patient. While FIG. 10 illustrates exemplary steps accordingto one embodiment, other embodiments may omit, add to, reorder, and/ormodify any of the steps shown in FIG. 10. One or more of the steps shownin FIG. 10 may be performed by fitting system 300 and/or anyimplementation thereof.

In step 1002, a fitting system directs, during a fitting session, an EASsystem to concurrently apply acoustic stimulation to a patient by way ofa loudspeaker and electrical stimulation to the patient by way of anelectrode located within a cochlea of the patient. Step 1002 may beperformed in any of the ways described herein.

In step 1004, the fitting system determines, during the fitting session,an interactive effect that the acoustic stimulation has on theelectrical stimulation. Step 1004 may be performed in any of the waysdescribed herein.

In step 1006, the fitting system sets, during the fitting session, oneor more acoustic stimulation control parameters governing an operationof the EAS system based on the determined interactive effect. Step 1006may be performed in any of the ways described herein.

In certain embodiments, one or more of the processes described hereinmay be implemented at least in part as instructions embodied in anon-transitory computer-readable medium and executable by one or morecomputing devices. In general, a processor (e.g., a microprocessor)receives instructions, from a non-transitory computer-readable medium,(e.g., a memory, etc.), and executes those instructions, therebyperforming one or more processes, including one or more of the processesdescribed herein. Such instructions may be stored and/or transmittedusing any of a variety of known computer-readable media.

A computer-readable medium (also referred to as a processor-readablemedium) includes any non-transitory medium that participates inproviding data (e.g., instructions) that may be read by a computer(e.g., by a processor of a computer). Such a medium may take many forms,including, but not limited to, non-volatile media, and/or volatilemedia. Non-volatile media may include, for example, optical or magneticdisks and other persistent memory. Volatile media may include, forexample, dynamic random access memory (“DRAM”), which typicallyconstitutes a main memory. Common forms of computer-readable mediainclude, for example, a disk, hard disk, magnetic tape, any othermagnetic medium, a CD-ROM, DVD, any other optical medium, a RAM, a PROM,an EPROM, a FLASH-EEPROM, any other memory chip or cartridge, or anyother tangible medium from which a computer can read.

FIG. 11 illustrates an exemplary computing device 1100 that may beconfigured to perform one or more of the processes described herein. Asshown in FIG. 11, computing device 1100 may include a communicationinterface 1102, a processor 1104, a storage device 1106, and aninput/output (“I/O”) module 1108 communicatively connected via acommunication infrastructure 1110. While an exemplary computing device1100 is shown in FIG. 11, the components illustrated in FIG. 11 are notintended to be limiting. Additional or alternative components may beused in other embodiments. Components of computing device 1100 shown inFIG. 11 will now be described in additional detail.

Communication interface 1102 may be configured to communicate with oneor more computing devices. Examples of communication interface 1102include, without limitation, a wired network interface (such as anetwork interface card), a wireless network interface (such as awireless network interface card), a modem, an audio/video connection,and any other suitable interface.

Processor 1104 generally represents any type or form of processing unitcapable of processing data or interpreting, executing, and/or directingexecution of one or more of the instructions, processes, and/oroperations described herein. Processor 1104 may direct execution ofoperations in accordance with one or more applications 1112 or othercomputer-executable instructions such as may be stored in storage device1106 or another computer-readable medium.

Storage device 1106 may include one or more data storage media, devices,or configurations and may employ any type, form, and combination of datastorage media and/or device. For example, storage device 1106 mayinclude, but is not limited to, a hard drive, network drive, flashdrive, magnetic disc, optical disc, random access memory (“RAM”),dynamic RAM (“DRAM”), other non-volatile and/or volatile data storageunits, or a combination or sub-combination thereof. Electronic data,including data described herein, may be temporarily and/or permanentlystored in storage device 1106. For example, data representative of oneor more executable applications 1112 configured to direct processor 1104to perform any of the operations described herein may be stored withinstorage device 1106. In some examples, data may be arranged in one ormore databases residing within storage device 1106.

I/O module 1108 may be configured to receive user input and provide useroutput and may include any hardware, firmware, software, or combinationthereof supportive of input and output capabilities. For example, I/Omodule 1108 may include hardware and/or software for capturing userinput, including, but not limited to, a keyboard or keypad, a touchscreen component (e.g., touch screen display), a receiver (e.g., an RFor infrared receiver), and/or one or more input buttons.

I/O module 1108 may include one or more devices for presenting output toa user, including, but not limited to, a graphics engine, a display(e.g., a display screen, one or more output drivers (e.g., displaydrivers), one or more audio speakers, and one or more audio drivers. Incertain embodiments, I/O module 1108 is configured to provide graphicaldata to a display for presentation to a user. The graphical data may berepresentative of one or more graphical user interfaces and/or any othergraphical content as may serve a particular implementation.

In some examples, any of the facilities described herein may beimplemented by or within one or more components of computing device1100. For example, one or more applications 1112 residing within storagedevice 1106 may be configured to direct processor 1104 to perform one ormore processes or functions associated with any of the facilities and/orsystems described herein.

In the preceding description, various exemplary embodiments have beendescribed with reference to the accompanying drawings. It will, however,be evident that various modifications and changes may be made thereto,and additional embodiments may be implemented, without departing fromthe scope of the invention as set forth in the claims that follow. Forexample, certain features of one embodiment described herein may becombined with or substituted for features of another embodimentdescribed herein. The description and drawings are accordingly to beregarded in an illustrative rather than a restrictive sense.

What is claimed is:
 1. A system comprising: a stimulation managementfacility configured to direct an electro-acoustic stimulation (“EAS”)system comprising an EAS device communicatively coupled to both aloudspeaker and a cochlear implant to concurrently apply acousticstimulation to a patient by way of the loudspeaker and electricalstimulation to the patient by way of an electrode communicativelycoupled to the cochlear implant; and a fitting facility communicativelycoupled to the stimulation management facility and configured to detectan interaction between the acoustic stimulation and the electricalstimulation, and set one or more control parameters governing anoperation of the EAS system based on the detected interaction.
 2. Thesystem of claim 1, wherein the interaction between the acousticstimulation and the electrical stimulation results in the acousticstimulation being suppressed by the electrical stimulation, and whereinthe fitting facility is configured to set the one or more controlparameters by adjusting the one or more control parameters in a mannerthat reduces the suppression of the acoustic stimulation by theelectrical stimulation.
 3. The system of claim 1, wherein theinteraction between the acoustic stimulation and the electricalstimulation results in the acoustic stimulation being suppressed by theelectrical stimulation, and wherein the fitting facility is configuredto set the one or more control parameters by designating the electrodeas being disabled.
 4. The system of claim 1, wherein the interactionbetween the acoustic stimulation and the electrical stimulation resultsin the acoustic stimulation being enhanced by the electricalstimulation, and wherein the fitting facility is configured to set theone or more control parameters by designating the electrode as anenhancing electrode through which enhancing electrical stimulation is tobe applied.
 5. The system of claim 1, wherein the interaction betweenthe acoustic stimulation and the electrical stimulation results in theelectric stimulation being suppressed by the acoustic stimulation, andwherein the fitting facility is configured to set the one or morecontrol parameters by adjusting the one or more control parameters in amanner that reduces the suppression of the electric stimulation by theacoustic stimulation.
 6. The system of claim 1, wherein the fittingfacility is further configured to determine an optimal crossoverfrequency associated with the acoustic stimulation and the electricalstimulation based on the detected interaction.
 7. A system comprising: astimulation management facility configured to direct an electro-acousticstimulation (“EAS”) system comprising an EAS device communicativelycoupled to both a loudspeaker and a cochlear implant to concurrentlyapply acoustic stimulation to a patient by way of the loudspeaker andelectrical stimulation to the patient by way of an electrodecommunicatively coupled to the cochlear implant; and a fitting facilitycommunicatively coupled to the stimulation management facility andconfigured to determine an interactive effect that the electricalstimulation has on the acoustic stimulation, and set one or moreelectrical stimulation control parameters governing an operation of theEAS system based on the determined interactive effect.
 8. The system ofclaim 7, wherein: the fitting facility is configured to determine theinteractive effect by determining that the electrical stimulation has asuppressive interactive effect on the acoustic stimulation; and thefitting facility is configured to set the one or more electricalstimulation control parameters by adjusting one or more properties ofthe electrical stimulation in a manner that reduces the suppressiveinteractive effect of the electrical stimulation on the acousticstimulation.
 9. The system of claim 7, wherein: the fitting facility isconfigured to determine the interactive effect by determining that theelectrical stimulation has a suppressive interactive effect on theacoustic stimulation; and the fitting facility is configured to set theone or more electrical stimulation control parameters by designating theelectrode as being disabled.
 10. The system of claim 7, wherein: thefitting facility is configured to determine the interactive effect bydetermining that the electrical stimulation has an enhancing interactiveeffect on the acoustic stimulation; and the fitting facility isconfigured to set the one or more electrical stimulation controlparameters by designating the electrode as an enhancing electrodethrough which enhancing electrical stimulation is to be applied.
 11. Thesystem of claim 7, wherein: the fitting facility is configured todetermine the interactive effect by determining that the electricalstimulation does not have either a suppressive or enhancing interactiveeffect on the acoustic stimulation; and the fitting facility isconfigured to set the one or more electrical stimulation controlparameters by designating the electrode as an electrode through whichstandard electrical stimulation is to be applied.
 12. The system ofclaim 7, wherein the fitting facility is configured to determine theinteractive effect by: recording an evoked response that occurs inresponse to the concurrent application of the acoustic stimulation andthe electrical stimulation; and comparing the evoked response to abaseline response that occurs in response to an application of theacoustic stimulation by itself; wherein, if the evoked response isgreater than the baseline response, the fitting determines that theelectrical stimulation has an enhancing interactive effect on theacoustic stimulation; and wherein, if the evoked response is less thanthe baseline response, the fitting facility determines that theelectrical stimulation has a suppressive interactive effect on theacoustic stimulation.
 13. The system of claim 12, wherein the evokedresponse comprises at least one of an intracochlear hair-cell responseand a neural response.
 14. The system of claim 12, wherein the fittingfacility is further configured to measure, prior to the recording of theevoked response that occurs in response to the concurrent application ofthe acoustic stimulation and the electrical stimulation, the baselineresponse by: directing the EAS system to apply the acoustic stimulation;recording an evoked response that occurs in response to the applicationof the acoustic stimulation; and designating the evoked response thatoccurs in response to the application of the acoustic stimulation as thebaseline response.
 15. The system of claim 7, wherein the fittingfacility is configured to determine the interactive effect bydetermining the interactive effect based on subjective feedback providedby the patient.
 16. A system comprising: a stimulation managementfacility configured to direct an electro-acoustic stimulation (“EAS”)system comprising an EAS device communicatively coupled to both aloudspeaker and a cochlear implant to concurrently apply acousticstimulation to a patient by way of the loudspeaker and electricalstimulation to the patient by way of an electrode communicativelycoupled to the cochlear implant; and a fitting facility communicativelycoupled to the stimulation management facility and configured todetermine an interactive effect that the acoustic stimulation has on theelectrical stimulation, and set one or more acoustic stimulation controlparameters governing an operation of the EAS system based on thedetermined interactive effect.
 17. The system of claim 16, wherein: thefitting facility is configured to determine the interactive effect bydetermining that the acoustic stimulation has a suppressive interactiveeffect on the electrical stimulation; and the fitting facility isconfigured to set the one or more acoustic stimulation controlparameters by adjusting one or more properties of the acousticstimulation in a manner that reduces the suppressive interactive effectof the acoustic stimulation on the electrical stimulation.
 18. Thesystem of claim 16, wherein the fitting facility is configured todetermine the interactive effect by: recording an evoked response thatoccurs in response to the concurrent application of the acousticstimulation and the electrical stimulation; and comparing the evokedresponse to a baseline response that occurs in response to anapplication of the electrical stimulation by itself; wherein, if theevoked response is greater than the baseline response, the fittingfacility determines that the acoustic stimulation has an enhancinginteractive effect on the electrical stimulation; and wherein, if theevoked response is less than the baseline response, the fitting facilitydetermines that the acoustic stimulation has a suppressive interactiveeffect on the electrical stimulation.
 19. The system of claim 18,wherein the fitting facility is further configured to measure, prior tothe recording of the evoked response that occurs in response to theconcurrent application of the acoustic stimulation and the electricalstimulation, the baseline response by: applying the electricalstimulation; recording an evoked response that occurs in response to theapplication of the electrical stimulation; and designating the evokedresponse that occurs in response to the application of the electricalstimulation as the baseline response.
 20. A method comprising: directingan electro-acoustic stimulation (“EAS”) system comprising an EAS devicecommunicatively coupled to both a loudspeaker and a cochlear implant toconcurrently apply acoustic stimulation to a patient by way of theloudspeaker and electrical stimulation to the patient by way of anelectrode communicatively coupled to the cochlear implant; detecting, bythe fitting system, an interaction between the acoustic stimulation andthe electrical stimulation; and setting, by the fitting system, one ormore control parameters governing an operation of the EAS system basedon the detected interaction.